复合封孔处理对汽车用5052铝合金草酸氧化膜性能的影响  

Effect of Compound Sealing Treatment on Performances of Ox⁃alic Acid Oxide Film on 5052 Aluminum Alloy for Automobile

作　　者：王玲玲 张元华[1,2] 赵江招 张莉[2] WANG Lingling;ZHANG Yuanhua;ZHAO Jiangzhao;ZHANG Li(Hebei Province Colleges and Universities Metal Material Process and Digital Forming Research and Development Center,Xingtai 054000,China;Hebei Institute of Mechanical and Electrical Technology,Xingtai 054000,China)

机构地区：[1]河北省高校金属材料加工与数字化成型应用技术研发中心,河北邢台054000 [2]河北机电职业技术学院,河北邢台054000

出　　处：《电镀与精饰》2020年第6期8-12,共5页Plating & Finishing

基　　金：河北省高等学校科学技术研究项目(ZD2019112)。

摘　　要：采用以草酸为主要成分的电解液对汽车用5052铝合金进行阳极氧化,为了进一步提高氧化膜的耐腐蚀性能,对其进行复合封孔处理。结果表明,封孔前后氧化膜的形貌有所变化,由多孔形貌转变为近无孔洞形貌,封孔后氧化膜表面除了Al、S、C和O四种元素,还检测到Ni和Si元素。封孔前氧化膜的腐蚀电位较铝合金正移了约420.0 mV,腐蚀电流密度降低了65%,极化电阻增加了近7倍,电荷转移电阻增加了约3.6倍,说明氧化膜能起到防止铝合金腐蚀的作用。氧化膜经复合封孔处理后,电化学参数进一步趋好,腐蚀电位、腐蚀电流密度、极化电阻和电荷转移电阻分别为-270.0 mV,1.04μA·cm^-2,19.94Ω·cm^2和23.69 kΩ·cm^2,耐腐蚀性能得到进一步提高。Anodic oxidation of 5052 aluminum alloy for automobile was carried out by using an electro⁃lyte with oxalic acid as the main component,and the oxalic acid oxide film was treated by compound sealing in order to further improve its corrosion resistance.The results showed that the morphology of oxide film before and after sealing changed from porous morphology to almost non-porous morphology,and the oxide film after sealing was composed of Al,S,C,O,Ni and Si.Compared with aluminum alloy,the corrosion potential of the oxide film before sealing moved forward about 420 mV,the corrosion current density decreased 65%,the polarization resistance increased nearly 7 times,and the charge transfer resistance increased about 3.6 times,indicating that the oxide film played a role in preventing the corrosion of the aluminum alloy.After the composite sealing treatment,the electrochemical parameters of the oxide film were further improved.The corrosion potential,corrosion current density,polarization resistance and charge transfer resistance were-270 mV,1.04μA·cm^-2,19.94Ω·cm^2 and 23.69 kΩ·cm^2,respectively.The corrosion resistance was further improved.

关 键 词：复合封孔处理 草酸氧化膜 汽车用5052铝合金 耐腐蚀性能 

分 类 号：TQ153.6[化学工程—电化学工业]